Feed mechanism having electrically-actuated releasing device



N. J. OLSSON. FEED MECHANISM HAVING ELEGTRICALLY ACTUATED RELEASING DEVICE.

APPLICATION FILED JULY 12, 1919.

Patented Mar. 2,1920.

I TED STA PTENT FFffiE NILS JOSEF OLSSON, OF GOTTENBQRG, SWEDEN, ASSIGNOR TO AKTIEBOLAGET SVEN'SKA KULLAGERFABRIKEN, OF GOTTENBDEG,

SWEDEN, A COE'PQBi-LTION 9F SWEDEN.

Specification of Letters Patent.

Patented Mar. 2,1920.

Application filed July 12, 1919. Serial No. 312,645.

To all whowz, it may concern:

Be it known that 1, Nine Josnr OLssoN, a subject of the King of Sweden, residing at Gottenborg, in the Kingdom of Sweden, have invented new and useful Improved Feed Mechanism Having Electrically-Actuated Releasing Devices, of which the following is a specification.

This invention relates to a feed mechanism having an electroresponsive releasing device which is adapted to be used in connection with machine-tools, and particularly in connection with grinding machines for manufacturing ball bearing rings and other works requiring a great accuracy as to their dimensions. It has already been proposed to use in connection with such machines a feeler in contact with the work which when the work reaches its desired size, in any suitable way controls the closing of an electric circuit by which the feeding device of the machine-tool, which usually consists of a pawl and ratchet gear, is brought out of operation.

Devices of said kind suffer from the drawback the electrical circuit does not heretofore known that the closing of 1n all cases result in an immedlate. stopping of the feed motion of the work as it may happen that the electric current cannot at once bring the pawl out of engagement with the ratchet if the closing of the current takes place while the feed movement is proceeding which results in that the work-piece will be worked more than is required.

This invention has for its object to provide a device of the above said kind by which the cutting off of the feed motion is secured under all circumstances as soon as the electric current is broken. The invention consists, chiefly in this that the armature of the electromagnet responsive to the cutting off current does not serve, as in the devices heretofore known, to directly bring the pawl out of engagement with the ratchet, but releases, when attracted, a yielding bearing device for said pawl so as to neutralize the power transmitting efiect of the latter as soon as the cutting off current is closed. 7

The invention is illustrated in the accompanying drawing which shows a preferred embodiment thereof. Figure 1 shows a sideelevation of the device and Fig. 2 shows a top plan view thereof. Fig. 3 is a detail view showing a pawl in the released position.

be engaged by Referring to the drawing 1 indicates a ratchet, and 2 a pawl cooperating therewith for the purpose of operatively turning it step by step. When the device is used in connection with a grinding machine, the ratchet 1 is connected by suitable means to a feed motion slide supporting the work. The pawl 2 is mounted by means of stud-pins 3 in elongated slots 4 in,a support 5 pivotally mounted by means of a stud-pin 6 in a lever 7 attached to an oscillating shaft 8. Inserted between the support 5 and the said lever is a spiral spring 9 tending to impart a clockwise rotation to the support (Fig. 1). This rotation is normally prevented by a latch arm 10 integral with the armature 11 of a releasing magnet 12 carried by the lever 7. The said latch arm 10 is formed with a notch adapted to a corresponding finger 13 formed on the support. The armature 11 is pivotally mounted on the stud-pin 1% and the hub of the said armature is flattened on its under side, as shown at 15, to afford a thrust for a piston 17 acted on by a spring 16 so as to yieldingly maintain the armature 11 in the normal position shown in Fig. 1. A spring 18 normally maintains the pawl 2 in engagement with the ratchet wheel. Secured to the stud pin 6 of the support 5 is an arm 19 by means of which the spring 9 may he wound up, if desired.

The operation of the device above described is as follows:

During the feeding operation, the shaft 8 with the lever mounted thereon is turned to and fro by any suitable means, not shown, so that the pawl 2 turns the ratchet 1 step by step. The slots 1 in the support 5 having in their normal position such a direction that the stud pin 3 of the pawl 2 is maintained in engagement with the lower ends of the slots 4: under the action of the feed pressure. When it is desired to cut off the feed motlon the circuit of the releasinfl magnet 12 is closed so that the latter will be energized and attracts its armature 11. By this attraction the lat h arm 10 is brought out of engagement with the finger 13 of the support 5 thereby releasing the support which under the action of the spring 9 is rotated in clockwise direction, until the slots 4 will lie approximately in the direc-' tion of the feed pressure. In case the pawl 2 is moving upwardly at this moment, it is prevented from transmitting any power to the ratchet l as the stud-pins3 of the pawl will slide downwardly in the slots 4:. At the end of the turning of the support the edge 20 thereof strikes the pawl 2 so as to throw over the latter to the position shown in Fig. 3 in which the pawl. is completely out of engagement with the ratchet wheel.

It should be understood that the details of the device described may be varied without departing from the principle of the invention. For instance, the slots 4 of the support may be substituted by an eccentric mounting of the support in relation to the stud-pins of the pawl so that the latter will be lowered upon the release and turning of the support. Further, the spring 9 may be substituted by a weight or the like.

Having thus described my invention, what I claim is l. The combination with a pawl, of a swinging arm supporting said pawl, a feedelement actuated by said pawl, means for holding the pawl in operative relation to said swinging arm and to said feed-element, and electrically actuated means for releasing said holding means.

2. The combination with a feed element, of a swinging arm, a support movably mounted in sald swinging arm, a pawl car-- ried by said support and electrically operated means for locking the said support in a position, relatively to the said swinging arm and the said pawl in which the pawl engages the feed element. I

3. The combination with a feed element, of a swinging arm, a support rotatably mounted in said arm, a pawl for engaging said feed element mounted in elongated slots in said support, and electrically actuated means for locking said support .in a position, in relation to the said arm and the said pawl in which the pawl engages the feed ele ment.

i. The combination with a feed element, of a swinging arm, a support rotatably mounted in said arm, a spring connecting said arm and said support to turn the latter so as to bring the pawl out of engagement with the feed element, and electrically operated means for preventing said action of the spring. 7

5. The combination with a feed element, of a swinging arm, a spring operated support rotatably mounted in said arm, a pawl mounted in said support, an armature for locking said support in a position in which the pawl is in engagement with the feed element, and an electromagnet cooperating with said armature to withdraw the armature from engagement with the support.

6. The combination with a feed element, of a swinging arm, a support rotatably mounted in said arm, a spring for turning said support in said arm, a pawl, rotatably mounted in said support, an abutment on said support for throwing the pawlout of engagement with the feed element, when the support is turned by the said spring, and electrically operated means for locking the support against said turning.

7. The combination with a feed element, of a pawl for actuating same, means for supporting said pawl, an electromagnet, an ar mature adapted to be actuated by said electromagnet, and serving, when retracted, to hold said means in operative condition, and spring operated means to yieldingly hold said armature in retracted position.

8. The combination with a feed element, of a swinging arm, a support rotatably mounted in said arm, a spring tending to turn said support in said arm, a pawl for actuating said fleed element mounted in elongated slots in said. support, an armature pivoted to said arm to lock the support against turning by the spring, and an electromagnet for attracting said armature, when energized, to Cc use it to release the said support thereby bringing the pawl out of operation.

In testimony whereof I have signed my name.

NILS JOSEF OLSSON. 

